4.1.4 Implement Custom Metrics (EMF)

import json

def handler(event, context):
    print(json.dumps({
        "_aws": {
            "Timestamp": 1705312200000,
            "CloudWatchMetrics": [{
                "Namespace": "MyApp",
                "Dimensions": [["Service", "Environment"]],
                "Metrics": [
                    {"Name": "OrderProcessingTime", "Unit": "Milliseconds"},
                    {"Name": "OrderCount", "Unit": "Count"}
                ]
            }]
        },
        "Service": "OrderService",
        "Environment": "prod",
        "OrderProcessingTime": 150,
        "OrderCount": 1
    }))

from aws_lambda_powertools import Metrics
from aws_lambda_powertools.metrics import MetricUnit

metrics = Metrics(namespace="MyApp", service="OrderService")

@metrics.log_metrics(capture_cold_start_metric=True)
def handler(event, context):
    metrics.add_metric(name="OrdersProcessed", unit=MetricUnit.Count, value=1)